external devices not working on PC

I don't know if this is a hardware problem or not but I can't use my camera or my printing machine and if I try the computer hangs on restart and turn off. I also tried to install a new spyware program and it installed but would not run. I than tried to restart and PC would not restart and Task Manager would not End Task on the new spyware. I have had to shut power off and than power back on to get computer back up. I am on Internet and Networking with router plus digital phone. I have no problem with the other programs on my computer and never had a problem with the camera or the printer. Any help in which direction I should go.

Thank you for your reply and yes I finally went into Device Manager and when I clicked on Hidden under Views I found two yellow ! under non-plug and play. One was: mrtRate and the other was: Genesys Logic USB Scanner Controller NT 5.0.

I try to do my own troubleshooting and usually I am pretty good at it but when it comes to looking deeper in
a computer I have no knowledge at all. I will find what I am instructed to look for but when I get there I am clueless. After restarting by turning off the computer twice I went back to the Device Manager and saw that the two above items were gone but my problem still exists. Now when I go to restart or turn off the computer it hangs for about 5 minutes or longer trying to shut down. If I even try to click on the Kodak icon to start my software the computer will freeze and I can't get it to even restart so I think it has something to do with that software. This all happened after I put my camera into the computer (USB Port) and tried to download the pictures. I did the same thing a week ago and everything was fine.